/**
 * Copyright (c) 2004-2006, Martin Fiedler.  All rights reserved.
 * Copyright (c) 2012, Ken Anderson.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, 
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 **/
 
#include "common.h"
#include "input.h"

FILE *input_fd=NULL;

extern int input_size;
extern int input_remain;
extern int ring_pos;
extern unsigned char ring_buf[RING_BUF_SIZE];

int input_open(const char *filename) {
  if(input_fd) {
    fprintf(stderr,"input_open: file already opened\n");
    return 0;
  }
  input_fd=fopen(filename,"rb");
  if(!input_fd) {
    perror("input_open: cannot open file");
    return 0;
  }
  fseek(input_fd,0,SEEK_END);
  input_size=ftell(input_fd);
  input_rewind();
  return input_size;
}

int input_read(unsigned char *dest, int size) {
  int count=fread(dest,1,size,input_fd);
  input_remain+=count;
  return count;
}

void input_rewind() {
  if(!input_fd) {
    fprintf(stderr,"input_rewind called, but no file opened!\n");
    return;
  }
  fseek(input_fd,0,SEEK_SET);
  input_remain=0;
  input_read(ring_buf,RING_BUF_SIZE);
  ring_pos=0;
}

void input_close() {
  if(!input_fd) return;
  fclose(input_fd);
  input_size=0;
  input_fd=NULL;
}
